Cyclinder/Piston

[drew250rnut]

Does anyone know if they make aftermarket jugs or will I just have to buy a new factory jug? Do they make aftermarket pistons bigger than .40 over? This is my first 250R and I am totaly rebuilding this bike so anything you guys can suggest would help me out alot. Thanks alot!!

Drew

[CorvetteZ06]

yes, aftermarket jugs are very popular, one of the most popular is Pro-X Cylinders, they are great.

[wilkin250r]

Many of the aftermarket cylinders start out as Pro-X cylinders with additional porting. So a "CT Racing 330 kit" is actually a Pro-X cylinder with a CT Racing port job.

[CorvetteZ06]

Originally posted by wilkin250r
Many of the aftermarket cylinders start out as Pro-X cylinders with additional porting. So a "CT Racing 330 kit" is actually a Pro-X cylinder with a CT Racing port job.


yep, thats what I have, the CT/PRO-X 310. Has been good for me so far! :cool:

[kiesta00]

why are you replacing the cylinder? something wrong with the stock jug?

[drew250rnut]

Hey Thanks guys! Yeah my stock jug needs bored to big and I don't think I can get a piston for it. It will have to be more than .40 over. Where can I get one of those jugs?
:confused:

[DanW]

Originally posted by drew250rnut
Hey Thanks guys! Yeah my stock jug needs bored to big and I don't think I can get a piston for it. It will have to be more than .40 over. Where can I get one of those jugs?
:confused:

Do you mean 0.40 over, or do you mean 0.040 over? 0.40 is almost 1/2 inch bigger than stock. If you need a piston that is .040 over or bigger, you can get Wiseco pistons up to at least .080 over.

[drew250rnut]

Originally posted by DanW
Do you mean 0.40 over, or do you mean 0.040 over? 0.40 is almost 1/2 inch bigger than stock. If you need a piston that is .040 over or bigger, you can get Wiseco pistons up to at least .080 over.


I need a piston bigger than .040 over. Where do i get one of thos? Rocky Mountian ATV only has .040 over I called them the other day. Thanks!!

Drew

[DanW]

Originally posted by drew250rnut
I need a piston bigger than .040 over. Where do i get one of thos? Rocky Mountian ATV only has .040 over I called them the other day. Thanks!!

Drew

You should try Colby at C&D Racing first. If he can't get it then I know that you can get them from Dennis Kirk.

[deathman53]

from alot of places you can get pistons to 80 over for 87-89 and 120-140? over for 85/86 pistons.

[drew250rnut]

Originally posted by DanW
You should try Colby at C&D Racing first. If he can't get it then I know that you can get them from Dennis Kirk.

Thanks!! Does C&D Racing have a web site?

[GPracer2500]

Originally posted by drew250rnut
Thanks!! Does C&D Racing have a web site?

They have their own forum in the "site sponsers" section right here on ATVriders. They probably have a stand-alone website too.

[wilkin250r]

C&D can definitely help you out.

If you want to try to make a go of it yourself, though, just to learn about these engines, forget Dennis Kirk. Go directly to the manufacturer's websites and look through the catalogs.

You'll see different part numbers for the 86 pistons and the 87-89 pistons. They are a different style, and not interchangable. Wiseco makes up to 69.50mm in the 86 piston (which is about .140 over, stock is 66mm), but only up to 68mm for the 87-89 piston (68mm is about 0.080 over).

Pro-X makes both styles up to 68mm over, and are a little better choice in my opinion.

As you are looking, keep this in mind. 1mm is about 0.040 inch. So a 66.25mm piston is about 0.010" over the stock 66mm, and so forth and so on.

[drew250rnut]

Thanks alot guys for all the help!!

Drew